The adopted it because they feared that if they were to intervene it would escalate. Also because the non intervention would prevent a war from happening in the European side of the world.
(let me know if you need a more detailed explanation)
The European nation that colonized India and Australia, in addition to having spheres of influence in China is Great Britain. They colonized India for two hundred years and sixty-two years with Australia. The sphere of influence with China has a certain levels of cultural, economical, cultural or political exclusivity.
The Crusades provoked the weakening of the feudal system as many of the hereditary lords died with their sons during the campaigns. With no one left to inherit, the lands were returned to the Crown. The Crusades saw a massive casualties on both sides. Millions perished through the endless wars and pillaging, and many more were taken into slavery, including thousands of children.
